Holy Grail War: Crossover Edition
by Moonsolol
Summary: What happens if Zelretch decided to mess around with the 5th Holy Grail War and made the Masters summon heroes from different universes?


"Aaaargh, is it time yet?"

A certain twin-tailed magus impatiently paced around a large basement cellar while constantly looking towards an old clock on the wall to her side. On the floor was an intricate red circle filled with indecipherable writings. In the center of it all was a hunk of black steel in a form similar to a gatling gun. However, it looked abnormal compared to modern versions, being different in design and more complicated in build.

"What the heck even is this catalyst? I was going to use the jewel I found in father's belongings, but for some reason Kirei handed me a package that was from Zelretch of all people! The actual Kischur Zelretch Schweinorg, the Wizard Marshall and user of the Second Magic! Why did he even come here in the first place?" Still pacing furiously, Rin Tohsaka glanced at the black catalyst lying in the center of the summoning circle. "Who is this even supposed to summon? In the letter that came with the package, Zelretch said that this… _thing_, is called, what was it, a 'Rock Cannon?' Why would someone make a gun to shoot rocks out of all things?"

Looking towards her clock again, she noticed that the hands were soon approaching the time she was aiming for; 2:00 AM. She was very fortunate that when the priest had visited to drop off her catalyst, he had noticed that all of her clocks were an hour behind for some reason. As a result, she managed to avoid a close call with messing up the ritual. "Alright, guess I'll start the summoning. If Zelretch came to give me a catalyst, then it should be a powerful one, right?"

Shaking off her inner doubt, Rin began the ritual to summon a Servant. Standing inside the magic circle and catalyst on the floor, she held up her arm, let some of her blood drip onto the circle, and began chanting:

_Silver and iron to the origin. Gem and the archduke of contracts to the cornerstone._

_The ancestor is my great master Schweinorg._

_The alighted wind becomes a wall. The gates in the four directions close, coming from the crown, the three-forked road that leads to the kingdom circulate._

_Shut (fill)._

_Shut (fill)._

_Shut (fill)._

_Shut (fill)._

_Shut (fill)._

_Repeat every five times._

_Simply, shatter once filled._

――――_I announce._

_Your self is under me, my fate(doom) is in your sword._

_In accordance with the approach of the Holy Grail, if you abide by this feeling, this reason, then answer._

_Here is my oath. I am the one who becomes all the good of the world of the dead, I am the one who lays out all the evil of the world of the dead._

_You, seven heavens clad in three words of power, arrive from the ring of deterrence, O keeper of the balance ―――__！_

Suddenly, a strong shockwave exploded from the center of the circle, alongside with a blast of wind. The room momentarily turned into a shade of crimson red, before the colors faded and the winds calmed down. Within the resultant smoke was a kneeling Rin, panting from the high amount of Mana that had just been taken from her to fuel the summoning.

"Haaa, haaa… did I succeed? Man, summoning a Servant is way more tiring than what I was expecting…" Slowly standing up, she took a gander around the room, but found no signs of any Servant or humanoid figure. "Huh, that's odd… the Servant should be around here…"

Suddenly, a loud crash happened above her head. "Huh? That came from the living room! What the hell?" Rin quickly rushed up the basement stairs and slammed open the door.

The scene that greeted her was a mess, to say the very list. Her living room was in tatters, and half of the roof had caved in somehow. Splinters of wood littered the carpet, and the air was filled with dust.

In the center of it all sat a shadowy figure on the sole surviving sofa. Rin could not make out any features just yet, but the figure seemed to look very skinny and petite. Its hair was in two disproportionate spiky twintails.

Without warning, the figure tilted its head up and stared at Rin's face. Rin was quickly taken aback by the seemingly glowing blue eyes of the girl in front of her. The girl's skin was extremely pale, and she was dressed in little clothes, only wearing a long black coat on top of a black bra and tight shorts. The girl blinked once, before standing up and bowing.

"Greetings, Servant Archer at your command. Are you my Master?"

* * *

Illya von Einzbern was having a rough day. No, rough was not enough to describe it; she was having a horrible day.

Having just arrived in Fuyuki City for the Fifth Holy Grail War, she was beyond excited to find her father, Kiritsugu Emiya, so that she could enact her wanted revenge on him for abandoning her back at the Einzbern Castle. However, to her despair, she discovered that Kiritsugu had already passed away a few years back.

She was shocked to discover that he had left behind an adopted son by the name of Emiya Shirou. She should have been the only child of Kiritsugu, yet he abandoned her and left to go raise another child in Japan. Her mind refused to accept any other truth, and planned to cause the downfall of this Emiya Shirou sooner or later. The Holy Grail War came first, though.

Illya started rubbing her left arm unconsciously. At the moment, she was only wearing her undergarments in preparation for her upcoming Servant summoning within the Einzbern castle. Her servants, Sella and Leysritt, had already finished setting up everything required for it to go well.

Two months ago, the Einzberns had planned for Illya to summon the legendary Greek hero, Hercules. He was the hidden game-changing piece the family had been holding onto since the last Grail War. However, the night before Illya was supposed to attempt to summon him early, the Wizard Marshall, Zelretch, had suddenly stopped by their castle, dropped a 'special' catalyst right into Jubstacheit's hands, and told him that unless he wants to experience something 'very entertaining,' I would be using the Wizard Marshall's given catalyst for the War. Jubstacheit had been highly annoyed and angry at Zelretch's sudden order, but could not go against his words, unless he wanted to be moved to a potentially horrific parallel dimension, ones the Wizard Marshall tended to drop people off into for his own entertainment.

Illya was not sure as to why the Wizard Marshall had made such a decision, but simply put it off as one of his usual whims. He would cause chaos in even the most important events, as long as he felt that his actions would be able to result in some fun for himself.

She looked towards the catalyst lying in the center of the summoning circle in front of her. It took the form of an orange pendant made out of an unknown crystalline material. The Wizard Marshall had called it a relic of sorts, but what catalysts were not relics in the first place?

Taking a deep breath, Illya stepped forward into the summoning circle her servants had prepared for her. A multitude of command seals covering her small body began to glow as she chanted out the lines required for the ritual. Near the end of the chant, she added a few lines not usually used for the other class summonings.

_Yet, thou serves with thine eyes clouded in chaos._

_Thou, bound in the cage of madness. I am she who command those chains._

The room began to turn into a dark shade of red as the ritual neared completion. Suddenly, a shockwave burst out from the center of the circle and winds blew like a tempest within the room. Sella and Leysritt quickly ran in front of Illya, ready to assist with any problems that may have occurred.

As the sparks and smoke cleared, Illya peeked open an eye to see who she had summoned. What was revealed was a female figure with short cream-colored hair wearing some sort of white and orange tightsuit-dress hybrid, with two gauntlets on each forearm. Her stomach was uncovered, and her lower legs were inside mechanical-looking boots. A white scarf wrapped around her neck, and a pair of orange-white headphones adorned her head. The orange pendant that had served as a catalyst laid lightly on her chest, transformed into a different shape. As her eyes opened, they revealed dark-orange irises, surprisingly empty of any signs of madness.

"Servant Berserker, here to help my Master anyway that I can."

* * *

With a final swipe of a towel, Emiya Shirou finally finished cleaning the last of the Homurahara High archery range floor.

"That should just about do it." Shirou quickly stood up and wiped the sweat off his forehead. "Looks like it's getting dark too, I should head back home soon, otherwise Taiga is going to get really worried." He threw the towel into a bin to the side and stretched his arms above his head. "Just need to head over to the gym sinks to clean off these towels and I'll be done."

Picking up the bin, Shirou left the range and began walking towards the school building. Thinking about what he would make for dinner, he almost missed a clanging sound that came from a distance away.

"Hm? What was that?" Shirou stuck out his ear in silence. Suddenly, another clang was heard. "From the courtyard?"

Slowly taking steps towards the sound, Shirou started thinking about what could be happening. _Is there some sort of maintenance work going on for a pipe? It's too late for someone to be working right now, though. Loiterers? That could be possible._

Soon, the courtyard came into Shirou's sights. What greeted him was something he could never have expected.

"Archer, watch out! That enemy servant's skin seems abnormal!" A twin-tailed girl shouted out towards the two superhuman combatants currently duking it out in the center of the courtyard. One side was a petite girl with two, disproportionate black twintails and a massive cannon on one arm. She wore a skimpy outfit, with only a long black trench coat covering most of her body. On the other side was a beautiful white-haired male wearing golden armor. A brilliant red stone was buried in the middle of his chest, and he was holding an intricate golden spear. The two were moving at untrackable speeds, flashing in and out of view and causing colorful sparks with each collision of their weapons.

"I'm surprised, to say the least. I was not expecting an Archer like you to be able to use such a bulky and unwieldy weapon in melee combat." The white-haried man spoke to the girl. Each word was delivered with complete calm. "However, that will not be enough against me."

The girl did not answer. Instead, she kicked off of the man's lance and raised the barrel of her cannon to his face in the blink of an eye. Shots began to pour out of the spinning barrel at the speed of a machine gun.

However, each round merely bounced off of his body. He swung his spear in a grandiose arc, and knocked the girl off to the side and straight through the walls of the school building.

_Snap._ With all of his attention aimed towards the impossible battle in front of his eyes, Shirou had not noticed the branch that had been right in front of his feet before he stepped on top of it.

In an instant, the white-haired male turned his head towards Shirou's position. "An intruder? How unfortunate this war is, that no witnesses must exist. I am extremely sorry, but I must silence you."

Shirou, now noticing his mistake, widened his eyes and swerved to run into the school building in hopes of escaping the unknown man. He rushed and tripped up the stairs in a desperate effort to escape. However, when he reached the second floor, he was greeted with a pale, unyielding figure, spear in hand.

"Again, this is the most unfortunate, but my Master cannot allow you to live after witnessing what you have seen. I am sorry, but there is no other option. However, I will at the very least let you know my name before I end your life. It is the least I can do."

With a simple thrust, the man's spear went straight through Shirou's heart and out the other end. "I am Karna, servant Lancer. I pray that you will have a good afterlife."

Karna pulled out the lance, and Shirou collapsed to the ground, blood pooling beneath his body. Before fading into the air, Karna gave Shirou one last look before leaving the scene.

As Shirou's vision began to blur and darken, he thought that he saw Rin running towards him with a red object in her hand. Seconds later, he fell into darkness.

* * *

**Author's Note: Heya, this is Moons here with a shitty crossover fanfic, woohoo! I haven't revealed all the servants yet, but so far we have these:**

**Saber: ?**

**Lancer: Karna from Apocrypha**

**Archer: Black Rock Shooter**

**Rider: ? **

**Caster: ?**

**Assassin: ?**

**Berserker: Hibiki Tachibana from Senki Zesshou Symphogear**

**All servants have already been chosen, so I am not accepting any requests. The choices will be surprising, to say the least!**

**But anyways, hope you guys enjoy!**


End file.
